Pump valve retainer

ABSTRACT

A retainer for movably securing a valve member within a fluid bore of a pump comprises a retainer head which includes at least one peripheral groove and a retainer hub which is connected to or formed integrally with the retainer head. The valve member is movably coupled to the retainer hub, and the retainer head is movable to position the groove over a radial protrusion in the fluid bore. In this position, the retainer is secured to the pump and the valve member is accordingly movably secured within the fluid bore.

BACKGROUND OF THE INVENTION

The present invention relates to reciprocating plunger and piston-typepumps which are used, for example, in oilfield operations. Inparticular, the invention is related to an improved valve retainer forsupporting a suction valve within the suction bore of the pump.

Plunger pumps for the oilfield industry generally include a plungerwhich is positioned in a plunger bore, a suction valve which ispositioned in a suction bore and a discharge valve which is positionedin a discharge bore. In operation, the plunger is reciprocated in theplunger bore to alternately draw fluid into the pump through the suctionvalve and then force the fluid out of the pump through the dischargevalve.

Prior art plunger pumps typically include a valve retainer forsupporting and guiding the suction valve within the suction bore.Without this valve retainer, the suction valve and its correspondingparts would be free to rise into the path of the plunger and therebydamage the plunger or other parts of the pump. In some pumps the suctionvalve and the retainer comprise a single assembly. In other pumps,especially larger pumps, the valve retainer is installed separately fromthe suction valve.

In these later types of pumps, various means are used to mount the valveretainer within the plunger bore or the suction bore. One example of aprior art valve retainer is the “longhorn” style valve retainer. Thesevalve retainers comprise a hub within which the stem of the suctionvalve is slidably received and two diametrically opposed “horns” whichare rotated into corresponding grooves formed in the suction bore tothereby secure the hub in place. However, these grooves create stressconcentrations within the suction bore which can reduce the serviceablelife of the pump.

SUMMARY OF THE INVENTION

In accordance with the present invention, these and other limitations inthe prior art are overcome by providing a novel valve retainer formovably securing a valve member within the fluid bore of a pump. Theretainer comprises a retainer head which includes at least oneperipheral groove and a retainer hub which is connected to or formedintegrally with the retainer head. The valve member is movably coupledto the retainer hub, and the retainer head is movable to position thegroove over a radial protrusion in the fluid bore. In this position, theretainer is secured to the pump and the valve member is accordinglymovably secured within the fluid bore.

In one embodiment of the invention, the retainer head comprises twoperipheral grooves, each of which is positionable over a correspondingradial protrusion in the fluid bore. In addition, these grooves may belocated approximately diametrically opposite each other on the retainerhead.

In accordance with one aspect of the invention, the retainer hubslidably engages the valve member. In particular, the retainer hub maycomprise a cylindrical bore within which a stem portion of the valvemember is slidably received.

In accordance with another aspect of the invention, the groove defines aperipheral lip which is located between the protrusion and the valvemember. In addition, although not necessary for purposes of the presentinvention, the circumferential length of the lip may be equal to orgreater than the circumferential length of the protrusion. Moreover, theretainer may comprise a cover for the lip, which is comprised of, forexample, an elastomeric material, in order to prevent metal-to-metalcontact between the lip and the protrusion.

In accordance with yet another aspect of the invention, the retainerincludes means for preventing the retainer from rotating relative to thefluid bore when the groove is positioned over the protrusion. Forexample, this rotation prevention means may comprise a retainer springwhich includes a first end which is secured to the retainer and a secondend which extends into the groove. Accordingly, when the groove ispositioned over the protrusion, the second end will enter a notch whichis formed in the protrusion and thereby prevent the retainer fromrotating relative to the fluid bore.

Thus, the present invention provides an effective mechanism forretaining the valve member within the fluid bore. Since the retainer isdesigned to engage a radial protrusion in the fluid bore, rather than arecess or a slot, the fluid bore is not subject to undue stressconcentrations. Therefore, the pump is less likely to fail duringoperation. Moreover, since the retainer comprises a lip which covers theprotrusion, the protrusion will not be likely to erode during extendeduse of the pump.

These and other objects and advantages of the present invention will bemade apparent from the following detailed description, with reference tothe accompanying drawings. In the drawings, the same reference numbersare used to denote similar components in the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of the fluid end of an illustrativeplunger pump which incorporates the valve retainer of the presentinvention;

FIG. 2 is an enlarged, partial cross section view of the plunger pumpfluid end taken along line A-A in FIG. 1;

FIG. 3 is a perspective view of the retainer head portion of the valveretainer of the present invention;

FIG. 4 is a cross sectional view of the protective boot component of thevalve retainer of the present invention;

FIG. 5 is a cross sectional view of the plunger pump fluid end shown inFIG. 1, but with the parts removed to more clearly show theconfiguration of the plunger and suction bores;

FIG. 6 is a cross sectional view of the plunger pump fluid end takenalong line B-B of FIG. 5; and

FIG. 7 is a partial cross sectional view of the fluid end of anillustrative plunger pump which incorporates another embodiment of thevalve retainer of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the valve retainer of the present invention, whichis indicated generally by reference number 10, is shown incorporatedinto the fluid end 12 of an exemplary plunger pump. The fluid end 12includes a housing 14 through which a plunger bore 16, a suction bore 18and a discharge bore 20 each extend. A plunger 22 is positioned in theplunger bore 16 and is sealed thereto by a conventional stuffing box 24which is secured to the housing 14 by, for example, a number of capscrews 26. A suction valve 28 is positioned in the suction bore 18between the plunger bore 16 and a pump inlet 30, and a discharge valve32 is positioned in the discharge bore 20 between the plunger bore and apump outlet 34. During assembly and servicing of the fluid end 12,access to the suction bore 18 may be attained through a first port 36which is sealed by a cover 38 that is secured to the housing 14 by afirst retainer nut 40, and access to the discharge bore 20 may beattained through a second port 42 which is sealed by a cover 44 that issecured to the housing by a second retainer nut 46.

Referring now to FIG. 2, the suction valve 28 is shown to comprise avalve member 48 which, in accordance with the present invention, isretained within the suction bore 18 by the valve retainer 10. The valvemember 48 includes a generally disc-shaped body 50, an annular seal ring52 which is disposed in a corresponding groove that is formed in thebody, an upper valve stem 54 which extends transversely from an upperend of the body, and a lower valve stem 56 which extends transverselyfrom a lower end of the body. The seal ring 52 is designed to engage acorresponding valve seat 58 which is formed on an upper end of acylindrical seat member 60 that is secured such as by press fitting in areduced diameter portion 62 of the suction bore 18. The lower valve stem56 is slidably received in a lower guide bushing 64 which is connectedto a perforated guide disc 66 that in turn is retained between the seatmember 60 and a shoulder 68 which is formed between the pump inlet 30and the reduced diameter portion 62 of the suction bore 18.

Referring also to FIG. 3, the valve retainer 10 includes an elongatedretainer head 70 and a transverse retainer hub 72. The retainer head 70comprises at least one and preferably two peripheral grooves 76. Thegrooves 76 are designed to engage corresponding radial protrusions 78which are formed in the suction bore 18 using any suitable machiningtechnique. As shown in FIGS. 5 and 6, each protrusion 78 extendscircumferentially around the suction bore a suitable distance, such asabout 28°, and is located, e.g., at the intersection of the suction borewith the plunger bore 16. If as shown in FIG. 3 the retainer head 70comprises two peripheral grooves 76 located diametrically opposite eachother, then the invention ideally also comprises two protrusions 78located diametrically opposite each other.

Each groove 76 defines a pair of upper and lower peripheral lips 80, 82between which a corresponding protrusion 78 is trapped to therebyprevent the valve retainer 10, and thus the valve member 48, from beingdrawn into the suction bore 16. Although not necessary for purposes ofthe present invention, the circumferential length of at least each lowerlip 82 may be greater than or equal to the circumferential length of itscorresponding protrusion 78 so that the lower lip will cover and protectthe protrusions against erosion caused by fluid flowing through thesuction bore 18. In addition, each lower lip 82 may be provided with acover or boot 84 which is made of, for example, a suitable elastomericmaterial and which serves to prevent metal-to-metal contact between thelip and the protrusion. Each boot 84 may be secured to its correspondinglower lip 82 by any suitable means. As shown in FIG. 4, such means maycomprise a pair of opposing dogs 86 which snap into correspondingrecesses or over corresponding detents formed on the lower lip.

In the embodiment of the invention shown in FIG. 2, the valve member 48is movably coupled to the retainer head 70 by the retainer hub 72. Theretainer hub 72 is connected to or formed integrally with the retainerhead 70 and includes a cylindrical bore 74 within which the upper valvestem 54 is slidably received. In addition, reciprocal movement of thevalve member 48 is aided in part by a spring 86 which is positioned overthe retainer hub 72 between the retainer head 70 and the body 50 of thevalve member.

To assemble the suction valve 28 within the suction bore 18, the guidedisc 66 is lowered onto the shoulder 68, the seat member 60 is mountedin the reduced diameter portion 62, and the lower valve stem 56 of thevalve member 48 is inserted into the guide bushing 64. At this point,the valve retainer 10 is ready to be installed. The valve spring 86 isfirst positioned over the retainer hub 72, and then the valve retainer10 is lowered into the suction bore 18 with the retainer head 70perpendicular to the protrusions 78 and the retainer hub positioned overthe upper valve stem 54. The valve retainer 10 is then pressed downagainst the force of the spring 86 until the grooves 76 are verticallyaligned with the protrusions 78. The valve retainer 10 is then rotatedapproximately 90° or until the upper lips 80 are oriented over theprotrusions 78. In this position, the valve retainer 10 is fixed withinthe suction bore 18 and the valve member 48 and the spring 86 areaccordingly prevented from being drawn into the plunger bore 16 duringoperation of the piston pump.

In operation of the piston pump 12, the plunger 22 is reciprocated by aconventional power end (not shown), which is connected to the housing 14and coupled to the plunger by conventional means. During the suctionstroke of the plunger 22, the valve member 48 is pulled off of the valveseat 58 and fluid is drawn through the inlet 30 and the suction bore 18and into the plunger bore 16. During the discharge stroke of the plunger22, the spring 86 will force the valve member 48 against the valve seat58 and the fluid will be re-directed through the discharge valve 32 andthe outlet 34. During both the suction stroke and the discharge stroke,the valve retainer 10 will guide the valve member 48 as it moves up anddown within the suction bore 18.

If desired, the retainer hub 72 and the guide bushing 64 may eachcomprise a bearing sleeve 88 within which the corresponding upper andlower valve stems 54, 56 are slidably received. The bearing sleeves 88may be secured within their corresponding bores in the retainer hub 72and the guide bushing 64 by any suitable means, such as set screws.

The valve retainer 10 may also comprise means for preventing the valveretainer 10 from rotating within the suction bore 18 after the grooves76 are positioned over the protrusions 78. Referring again to FIG. 2,the rotation prevention means in accordance with one embodiment of theinvention includes a retainer spring 90 which is mounted in a narrow,trough-shaped aperture 92 that is formed in the retainer head 70. Theretainer spring 90 comprises a first end 94 which is inserted into acorresponding hole 96 in the retainer head 70 and a second end 98 whichextends through an aperture 100 in the retainer head and into anadjacent groove 76. As the retainer head 70 is rotated to align thegrooves 76 with the protrusions 78, the second end 98 of the retainerspring 90 will cam over one of the protrusions 78 and, when the grooves76 are properly aligned with the protrusions 78, snap into a notch 102which is formed in the protrusion, thereby preventing the valve retainerfrom rotating relative to the protrusions. If the need to remove thevalve retainer 10 arises, the second end 98 of the retainer spring 90may be lifted out of the notch 102 by a suitable tool and the retainerhead 70 rotated until the grooves 76 are clear of the protrusions 78, atwhich point the valve retainer may be lifted out of the suction bore 18.

Another embodiment of the valve retainer of the present invention isillustrated in FIG. 7. The valve retainer of this embodiment, which isindicated generally by reference number 110, is shown installed in thesuction bore 18 of the fluid end 12 of an exemplary plunger pump. Aswith the previous embodiment, the function of the valve retainer 110 isto retain and guide a valve member, generally 112, within the suctionbore 18 during operation of the pump. Unlike in the previous embodiment,however, the valve member 112 does not include an upper valve stem.Rather, the valve member 112 comprises a number of depending legs 114which are slidably received within the seat member 60 in order to guidethe valve member along the axis of the suction bore 18.

In the embodiment of the invention shown in FIG. 7, therefore, the valvemember 112 is movably coupled to the valve retainer 110 solely by thespring 86. Although the valve retainer comprises a somewhat truncatedretainer hub 72, this is provided mainly as a radial guide for the upperportion of the spring 86.

It should be recognized that, while the present invention has beendescribed in relation to the preferred embodiments thereof, thoseskilled in the art may develop a wide variation of structural andoperational details without departing from the principles of theinvention. Therefore, the appended claims are to be construed to coverall equivalents falling within the true scope and spirit of theinvention.

1. In combination with a pump which comprises a fluid bore and a valvemember which is positioned in the fluid bore, the fluid bore comprisinga central axis and a pair of generally diametrically opposed, radiallyinwardly extending protrusions, the improvement comprising a retainerfor the valve member which includes: a retainer head which comprises apair of generally diametrically opposed peripheral grooves, each ofwhich is defined by a corresponding pair of upper and lower peripherallips; a retainer hub which is connected to or formed integrally with theretainer head and to which the valve member is movably coupled; whereinthe retainer is rotatable in a plane generally perpendicular to thecentral axis to position each pair of upper and lower lips over acorresponding one of the inwardly extending protrusions to therebysecure the retainer to the pump and movably secure the valve memberwithin the fluid bore; and an elongated retainer spring which ispositioned in an open aperture that extends diametrically through theretainer head between the grooves, the retainer spring including a firstend which is secured to the retainer head proximate one of the groovesand a second end which extends into the other of the grooves; whereinwhen the retainer is rotated to position the lips over theircorresponding protrusions, the second end will enter a notch which isformed in one of the protrusions and thereby prevent the retainer fromrotating relative to the fluid bore.
 2. In combination with a pump whichcomprises a fluid bore and a valve member which is positioned in thefluid bore, the fluid bore comprising a central axis and a pair ofgenerally diametrically opposed, radially inwardly extendingprotrusions, the improvement comprising a retainer for the valve memberwhich includes: an elongated retainer head which comprises twoperipheral grooves that are located approximately diametrically oppositeeach other, each peripheral groove being defined by a corresponding pairof upper and lower peripheral lips; a retainer hub which is connected toor formed integrally with the retainer head and which includes acylindrical bore within which a stem portion of the valve member isslidably received; wherein the retainer is rotatable in a planegenerally perpendicular to the central axis to position the grooves overthe protrusions to secure the retainer to the pump and thereby slidablysecure the valve member within the fluid bore; and an elongated retainerspring which is positioned in an open slot that extends diametricallythrough the retainer head between the grooves, the retainer springincluding a first end which is secured to the retainer head proximateone of the grooves and a second end which extends into the other of thegrooves; wherein when the retainer is rotated to position the lips overthe inwardly extending protrusions, the second end will enter a notchwhich is formed in one of the protrusions and thereby prevent theretainer from rotating relative to the fluid bore.
 3. The combination ofclaim 2, wherein the second end of the retainer spring extends throughan aperture which is formed between the slot and the groove.